This thesis deals with the development of a Visual Densitometer, for measuring transmission density, called a "Null-Balance Visual Densitometer". This is a simple instrument made using a calibrated continuous tone negative step wedge. It was used for measuring continuous tone reference patches as used for process control of color separations, in place of an electronic densitometer. The measurements were made by a comparison between the control step wedge and the samples in close proximity over a light table. The basis for this instrument is the human eye's ability to differentiate between two areas of brightness in close proximity. The study involved 20 operators making visual comparisons of 22 samples that ranged between 0.20 and 2.04, two sets of measurements were made to determine if the surrounding light from the light table had an effect on the results. The test proved that the variation of the instrument as tested was greater than that is necessary for process control when making color separation negatives, (larger than 0.03) .
Library of Congress Subject Headings
Color separation--Quality control; Color printing--Quality control; Optical measurements
Department, Program, or Center
School of Print Media (CIAS)
Baez, Ramon P., "A null-balance visual densitometer" (1987). Thesis. Rochester Institute of Technology. Accessed from
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